Which subs should i buy?

I'm sure the polks did blow the alpine away because there's two of them and they are 2" bigger. I would use the Kicker or the Alpine mainly because they are name brand. The bigger companies subs last a whole lot longer and sound better (my opinion). I had 2 10" Pioneers in my truck with a dual 750 Pioneer amp (1500 total). I traded up to get 12" Pioneers and the same amp. It hits great. I recommend pioneer but since you don't have that there I would say the Kicker.